I open up when rain falls down and close when skies are clear. I shield your head without a sound whenever storms appear. What am I?

I run but never walk, I murmur, don’t talk, I have a bed but never sleep.

I glide on a mirror without any wheels, A coat of pure snow from my head to my heels. With a neck like an 'S' and a royal, calm grace, I rule over ripples in my watery place.

Glorious trees, sometimes with a weeping sounding name, that stand tall and proud, providing lots of shade.

I wear a suit of armored scales, With jaws that snap and a tail that flails, A swampy king, where danger prevails.